Such an apparatus of the prior art is described in, for example, Japanese Patent Laid-Open No. 2-123065. In this invention, a transport apparatus for transporting a transfer sheet includes a suction device for sucking the transfer sheet and a switching device for switching the suction force according to the stiffness of the transfer sheet.
In an apparatus described in Japanese Utility Model Laid-Open No. 5-5755, a suction duct including a suction fan is provided to suck air from the inside of an exposure house and the sucked air is exhausted in a circulating manner from an air outlet to the top surface of a sheet photosensitive material through an air supply duct extending upward along the optical axis of the exposure house.
In an apparatus described in Japanese Utility Model Publication No. 7-29074, a belt is provided for scanning in a certain direction a side of a substrate having air suction holes formed thereon, a plurality of suction ducts are extended so as to cross the scanning direction of the belt and are connected to an exhausting device, and the exhaust holes of the suction ducts are reduced in cross-sectional area as the air suction holes of the suction ducts come closer to the exhausting device.
In an apparatus described in Japanese Patent Laid-Open No. 2006-89223, the inside of a chamber is divided into two adjacent spaces by a diaphragm, air is passed through an upstream chamber to generate a suction force in a transport direction upstream from an image forming region, and air is passed through a chamber for the image forming region to generate a suction force in the image forming region and downstream of the image forming region.